invention relates generally to folding doors and partitions and is particularly directed to a multi-section, high speed, motor driven, impact-resistant folding door.
Electrically operated folding partitions, or doors, having a plurality of vertically oriented panels are commonly used in doorways to provide isolation between two rooms or between the outside and inside of a building. Such folding partitions are also frequently used to divide off two or more areas of a given room. The vertically oriented panels are typically suspended from a longitudinal, horizontal track along which the panels are movable. The panels may be coupled together in an accordion-like manner or they may be detached from one another such as in a strip door. Where the panels are coupled together, they are automatically positioned in a straight line, flat arrangement when in the fully closed position and are automatically moved to a folded, stacked configuration when in the fully open position. Such structures are often referred to as operable walls in that they provide a movable wall section for space isolation purposes.
Although not intended to afford high impact resistance, the individual panels of these folding door, or moving wall, arrangements are sometimes struck by a vehicle when in the closed position or when moving between the closed and the open positions. Such panel impact frequently causes the panel support mechanism, i.e., a movable trolley, to come off its support track preventing further displacement of the panels. High winds resulting in excessive displacement of the panels may also give rise to trolley binding on the support track. Misalignment between the trolleys and the support track must be corrected by proper repositioning of the trolleys before the panels can again be moved to either the open or closed position. Impact with a panel also frequently results in panel damage requiring its replacement. Panel replacement is expensive and time consuming, typically requiring removal of a mounting assembly which includes several brackets and nut and bolt combinations. In addition, adjacent suspended panels are coupled together in a flexible manner by ropes or straps which prevent separation of adjacent panels. However, impact of the panels with a vehicle generally results in severance of the rope, which must then be replaced, as well as damage to the adjacent panels which also frequently must be replaced. Moreover, such nonseparable coupling arrangements prevent manual pivoting displacement of the individual door panels so as to allow for transit through an aperture spanned by the door when power is lost. Finally, in order to prevent trolley misalignment and panel separation from its trolley-coupled mounting arrangement, particularly where the panels are subject to vehicular impact as well as to a wide range of environmental conditions, existing trolley and panel support installations are overly complex, expensive and difficult to install and maintain.
The present invention is intended to overcome the aforementioned limitations of the prior art by providing a multi-panel, high speed folding door having an inexpensive panel suspension arrangement which facilitates individual panel installation, removal and replacement; breakaway coupling between adjacent panels to reduce the possibility of impact damage to the panels; and self-aligning trolleys which maintain sliding engagement along the length of an overhead support beam even when the panels are subjected to large lateral forces and undergo substantial displacement as a result thereof.